AmA£«srt,i894!"m'}  Contributions  to  Pharmacy.  405 
which,  upon  exposure  to  air,  takes  up  water,  becomes  black,  gradually 
deliquesces,  and,  by  absorption  of  carbon  dioxide,  liberates  again 
resinotannol ;  by  repeating  the  solution  and  precipitation  it  was 
possible  to  almost  quantitatively  change  the  alcohol  from  Peru- 
balsam  resin  into  its  potassium  compound  ;  this  compound  is  very 
soluble  in  water  and  is  decomposable  by  addition  of  acids.  The 
resinotannol  from  Peru-balsam  in  properties  is  similar  to  that  from 
benzoin,  but  chiefly  because  of  its  different  ultimate  composition  it 
is  called  Peru-resinotannol.  Its  properties,  as  far  as  they  have 
not  already  been  described,  are :  Light  brown,  bulky,  odorless 
powder,  neutral  reaction,  heavier  than  water,  soluble  in  solutions  of 
alkalies  and  alkaline  carbonates,  in  acetone,  glacial  acetic  acid  and 
alcohol  (water  precipitates  it  again  from  the  last  two  solvents) ; 
carbon  disulphide  takes  up  traces,  and  in  petroleum-ether  it  is  in- 
soluble ;  assisted  by  moderate  heat  cinnamei'n  dissolves  it  with  a 
brown  color ;  the  addition  of  alcohol  to  this  solution  produces  no 
precipitate,  but  the  addition  of  ether  does ;  it  could  not  be  crystal- 
lized from  any  of  its  solvents  ;  concentrated  sulphuric  acid  dissolves 
it  with  red-brown  color ;  hydrochloric  acid  colors  it  black  (a  prop- 
erty also  possessed  by  the  oak-phlobaphenes) ;  concentrated  nitric 
acid  oxidizes  it  to  oxalic  and  picric  acids;  dilute  nitric  acid  produces 
only  picric  acid.  The  following  reactions  point  to  its  relations  to 
the  tannins :  In  alcoholic  solution  it  produces  with  lead  acetate  a 
yellowish,  with  potassium  bichromate  a  brownish-yellow  precipitate, 
and  with  ferric  chloride  a  red-brown  precipitate,  if  water  be  added 
to  the  alcoholic  solution  until  a  turbidity  is  produced.  This  reac- 
tion with  lead  acetate  was  used  in  purifying  the  compound  for 
analysis,  the  precipitate  suspended  in  alcohol  was  decomposed  by 
hydrogen  sulphide,  the  filtrate  diluted  with  water  and  acidified 
hydrochloric  acid;  the  precipitated  Peru-resinotannol  was  then  ob- 
tained free  from  ash  by  repeated  solution  in  ammonia  and  precipita- 
tion with  hydrochloric  acid  ;  the  ultimate  analysis  gave  carbon 
68  3  per  cent.;  hydrogen,  6  3  per  cent.;  oxygen,  by  difference,  25-4 
per  cent.;  nitrogen  was  proven  to  be  absent ;  the  formula  calculated 
from  the  analysis  of  the  pure  substance  and  a  number  of  its  deriva- 
tives is  C18H20O5.  The  following  derivatives  were  also  prepared  and 
analyzed:  potassium  derivative,  C18H19K05;  acetyl  derivative  y  C18H19 
(C2HsO)05 ;  benzoyl  derivative,  C18H19(C7H50)05.  The  cinnamyl 
derivative  could  not  be  obtained  pure  enough  for  analysis  ;  neither 
could  a  crystallizable  or  uniform  bromine  product  be  obtained. 
